For standard genealogical data, these platforms are your starting point:

Often, the search for a stepfamily is actually a search for the half-siblings caught in the crossfire. If you share a biological parent with someone in that family, DNA testing (AncestryDNA or 23andMe) is the most effective tool. Even if they haven’t tested, a distant cousin might lead you to them. 5. Prepare for the "No-Win" Scenario

When meeting them didn’t (often)

Before you hit the search bars, ask yourself: Closure: Do you need to tell them how they hurt you?